What constitutes a correction?

“Sex and Significance” orig­i­nally said: “That means 10 heads in a row is sig­nif­i­cant ev­i­dence that the coin is biased; eight heads isn’t.” This is not right, so I emailed the author and Slate cor­rec­tions department; the author sub­se­quently wrote back saying that it should be changed, and a few hours later the sen­tence was changed to read: “That means 10 heads in a row is sig­nif­i­cant ev­i­dence that the coin is biased; eight out of ten isn’t.”

The mistake and sub­se­quent change wasn’t noted on Slate’s seem­ingly com­pre­hen­sive Corrections column. (Seemingly com­pre­hen­sive because it in­cludes such cor­rec­tions as “blogger Colin Hen­der­son was re­ferred to as”Harrison" on a second ref­er­ence due to an editing error." Isn’t this un­nec­es­sar­ily self-flaggellating? Can’t you just fix this?) So, what cor­rec­tions get reported, and what don’t?